2014-04-03 FCST: AR, MO, IL, IN, TN, KY, MS

[Bob Hartig]

Time to initiate a discussion for Thursday's potential weather event. I've cheated and consulted the SPC day 3 graphic's core states, but others may need to be added. My personal area of interest, based on regional bias, is Missouri and Illinois, which are within easy reach of where I live in Michigan.

Until recently, the models had been quite out of sync with each other, with the Euro in particular moving the surface low all over the map. But these past few runs have seemed to settle in, and the NAM--which initially wanted to race the system eastward--now has slowed down in tandem with the Euro and GFS. It's still the most optimistic about how far north the warm front and low-to-mid-60s dewpoints will make it, but I like that, and I hope it's on the money. Whichever solution verifies, all three models roughly agree that Missouri is poised to get slammed, and I'm presently casting my eyes on an area roughly around Columbia as a good initial target. Here's this evening's 00Z NAM skew-T for Columbia on Thursday at 23Z. Not bad. The SBCAPE looks juicy, and the hodo, while not the curviest in creation, certainly shows enough helicity to get the job done.

 

[Bob Hartig]

To be honest, Austin, it's a matter of my location. I'd prefer to head farther south to the boot heel, but for me, that's the difference between a day chase and an overnight, and more cash from a tight budget. So it's a matter of practicality, of taking what I can get. Surface winds tend to back along a warm front, enhancing low-level helicity, which is a plus. More robust conditions lie farther south, where richer moisture and a much stronger low-level jet are forecast. But that area is mountainous till it opens up into the Mississippi floodplain. In any case, the northern part of the system has enough going for it that it seems worth the drive. It's a matter of regional bias; if I lived where you do, I'd be quite happy, but I'd also be thinking about heading farther south.

 

[Eric Matthews]

This looked like a slam dunk day, but now that I've looked at the 03UTC RAP, there are several factors that are making things a little more challenging. Please excuse the wandering nature of this post, but I'm just throwing out some quick observations from a non-meteorological mind!

First, the upper level low is pushing further N rather than NE as earlier projected. It looks to be in SE/S Central Iowa by 21UTC.
Next, the upper level trough, while still becoming negatively tilted as it moves east, has slowed.
Next, the SRH has dropped from a projected 250-300 m2/s2, to under 150 m2/s2 and that is only in the SE quadrant of Missouri (a most challenging chase area)
I was hoping the height falls from the upper level low would weaken a stout cap and allow initiation along the dry line (Joplin to Tulsa) to allow chasing in a very slightly better area. With the trough trailing so far behind, it will be unavailable to provide the necessary mid-level cooling. Now I'm not certain storms can fire and move off the line before becoming a QLCS.
The warm front is projected to be along the Missouri/Iowa border, but there does not appear to be nearly as much SBCAPE as previously forecast.

I'm interested to see the next couple runs of the RAP to see what things look like after 21UTC... I'll be chasing, but where and when I'm still not sure.

 

[Dan Robinson]

I have the same concerns that Eric outlined. All along, the models have had the core of the jet streak far behind the instability axis - not a huge problem, as there is nonetheless plenty of flow to the east to make it happen. The surface low/warm front had been my obvious play, but at this point I'm back to square one with all options open. I'm anxiously watching the current MCS, hoping it makes its turn to the east soon and gets on out of Dodge. If not, things will be very muddy indeed. Morning satellite, as usual, will be the big 'reveal' of how this day is going to play out.